Duchenne muscular dystrophy is most common in males, and is characterized by muscle weakness that progresses over time. Onset is as early as three years of age and the life expectancy varies by patient, but can be as early as late teens, to a patient living in their 50s. There is no treatment to stop it’s progression.
When it comes to treating diseases, a lot of medicines target the symptoms, which doesn’t “fix” the issue; it just helps manage it. So patients just keep taking meds to help control pain, but they don’t necessarily get better.
This is obviously not ideal– we want to get better! To illustrate my point: If you have something as trivial as a flat tire, you don’t just continue to inflate it without actually finding the cause of the leak, because if you do that, the leak keeps happening and you have to keep inflating the tire. You find the source of the leak and patch it up.
So, if researchers know why certain symptoms keep happening and getting worse, treatments can be targeted to prevent the disease from continuing to wreak havoc on our bodies. In a sense, if they can find the source of leak, they can patch it up.
This most recent DMD discovery could do just that for the muscular dystrophy community.
Scientists at The University of Pennsylvania found that teens suffering from DMD have muscle stem cells with shorter telomeres than those who are not suffering from DMD.
What the heck is a stem cell telomere and why does it matter? Well, stem cells are responsible for cell regeneration and repair. If you have a muscle tear, stem cells divide to help repair that muscle. Telomeres are caps at the end of our chromosomes that protect the DNA chain. When stem cells copy themselves, the telomere keeps getting shorter with every regeneration. When telomeres get too short, the cell ages and stops doing it’s job– it can no longer heal that torn muscle.
Patients with DMD have fragile muscle fibers, causing them to be damaged by even the simplest of tasks. So, theoretically, muscle stem cells will regenerate those torn muscle fibers to heal it. However, the continuous regeneration of muscle fibers could be speeding up the lifetime of telomeres in cells, resulting in early dysfunction and subsequent death.
So, the discovery of shortened telomeres in muscle stem cells of teens with DMD could be why muscle wastes away so quickly, resulting in cell death.
If researchers can come up with a way to stop the rapid telomere shortening, it could thwart the disease progression and maybe even help muscle regeneration in those battling muscular dystrophy. Additionally, if scientists can treat patients with newer genetic therapies before it gets to the point of the telomeres becoming too short, they can sustain muscle-regeneration abilities in those stem cells.